1. Field of the Invention
The present invention relates to an electric connector box having a casing in which a circuit substrate is housed.
2. Description of Related Arts
For example, JP-A-2004-40873 discloses an electric connector box for distributing power from a vehicle-mounted power source to various electric and electronic parts. The described electric connector box takes in the form of a casing having a frame, in one opening of which a heat radiator plate is mounted and in the other opening of which a cover is mounted. A circuit substrate is housed within the casing. A mounting bracket for mounting the electric connector box on a vehicle is formed on the heat radiator plate and the electric connector box is mounted to a body of the vehicle by screwing a bolt into a bolt hole formed in the mounting bracket.
Since large current flows from the power source through the circuit substrate, an amount of heat generated in the circuit substrate becomes relatively large correspondingly to the current. When temperature in the electric connector box due to heat generated by the circuit substrate becomes high, the electric and electronic parts mounted on the circuit substrate may operate erroneously or may be deformed. Therefore, it is preferable to rapidly radiate heat generated by the circuit substrate externally from the connector box. In the prior art electric connector box, heat generated from the circuit substrate is radiated by mounting a heat radiator plate on the circuit substrate through an insulator material and making the heat radiator plate in contact with the body.